User-facing AssertionError with groupby on list of empty list. · Issue #5289 · pandas-dev/pandas (original) (raw)

I hesitate to post this, but grouping on a list of empty list yields an AssertionError. It's so edge case I'm not sure it's worth bring up though:

df = pd.DataFrame(zip(range(10), range(10)), columns=['apple', 'b']) df.groupby([[]])

Long traceback yields: AssertionError: Grouper and axis must be same length

Came from this SO issue (but it's really only related because of the error message) - http://stackoverflow.com/questions/19483991/how-to-make-grouper-and-axis-the-same-length